Electrophotographic photoconductor for wet developing and image-forming apparatus for wet developing

Abstract

Provided are an electrophotographic photoconductor for wet developing excellent in solvent resistance having a photoconductor improved in not only solvent resistance but also charging characteristics even after long-term usage, and an image-forming apparatus equipped with such an electrophotographic photoconductor for wet developing.

Therefore, an electrophotographic photoconductor for wet developing equipped with an organic photoconductor containing at least a binder resin, a charge-generating agent, a hole-transfer agent and an electron-transfer agent, where the amount of elution of the hole-transfer agent after 2,000-hour-immersion in paraffin solvent having a kinematic viscosity (25° C., in accordance with ASTM D455) of 1.4 to 1.8 mm²/s is 0.040 g/m² or less or the amount of elution of the electron-transfer agent after 2,000-hour-immersion in paraffin solvent having a kinematic viscosity (25° C., in accordance with ASTM D455) of 1.4 to 1.8 mm²/S is 0.12 g/m²2 or less.

Description

TECHNICAL FIELD [0001] The present invention relates to an electrophotographic photoconductor for wet developing and an image-forming apparatus for wet developing, and in particular to an electrophotographic photoconductor for wet developing excellent in solvent resistance and to an image-forming apparatus for wet developing equipped with such an electrophotographic photoconductor for wet developing. BACKGROUND ART [0002] Conventionally, organic photoconductors, which are made of organic photoconductor materials such as charge-transfer materials (hole-transfer agents and electron-transfer agents), charge-generating agents and binder resins, have been widely used as electrophotographic photoconductors for wet developing equipped in an image forming apparatus and so on. The organic photoconductors are advantageous in its simplicities of manufacturing processes and configurations, compared to a conventional inorganic photoconductors. In addition, there is another advantage in easy wet ...

AI Technical Summary

Benefits of technology

[0012] According to the electrophotographic photoconductor for wet developing of the invention, by limiting the amount of elution of a hole-transfer agent from a photoconductive layer in the duration of 2,000 hours, the solvent resistance, sensitivity characteristics and charging characteristics of the electrophotographic photoconductor for wet developing may be estimated in case of long-term usage such as image formation on 100,000 sheets of paper. In addition, the invention also focuses on the amount of elution of the hole-transfer agent when the hole-transfer agent are immersed into predetermined paraffin solvent under the predetermined condition, the solvent resistance of the electrophotographic photoconductor for wet developing in long-term usage may be increased, while the sensitivity characteristics and charging characteristics thereof to be precisely estimated. Alternatively, by limiting the amount of the elution of the hole-transfer agent in the duration of 200 hours, not only for 2000 hours, the solvent resistance, sensitivity characteristics and charging characteristics of the electrophotographic photoconductor for wet developing after long-term usage may be estimated in relatively short time.

[0013] According to the electrophotographic photoconductor for wet developing of the invention, by limiting the amount of elution of an electron-transfer agent from a photoconductive layer in the duration of 2,000 hours, the solvent resistance, sensitivity characteristics and charging characteristics of the electrophotographic photoconductor for wet developing may be estimated in case of long-term usage such as image formation on 100,000 sheets of paper. In addition, the invention also focuses on the amount of elution of the electron-transfer agent when the electron-transfer agent are immersed into predetermined paraffin solvent under the predetermined condition, the solvent resistance of the electrophotographic photoconductor for wet developing in long-term usage may be increased, while the sensitivity characteristics and charging characteristics thereof to be precisely estimated.

[0014] Alternatively, by limiting the amount of the elution of the electron-transfer agent in the duration of 200 hours, not only for 2000 hours, the solvent resistance, sensitivity characteristics and charging characteristics of the electrophotographic photoconductor for wet developing after long-term usage may be estimated in relatively short time.

[0015] In addition, according to the electrophotographic photoconductor for wet developing of the invention, a hole-transfer agent may be prevented from crystallization by defining the amount of addition of the hole-transfer agent within the predetermined range, and an electrophotographic photoconductor for wet developing excellent in sensitivity characteristics may be provided.

[0016] According to the electrophotographic photoconductor for wet developing of the invention, by defining the molecular weight of a hole-transfer agent within a predetermined value, only a small amount of the hole-transfer agent is eluted even after long-term immersion in hydrocarbon-based solvent used as a developer for wet developing. In addition, the electrophotographic photoconductor for wet developing may also provide excellent solvent resistance and durability because the hole-transfer agent has good compatibility with the binder resin.

[0017] According to the electrophotographic photoconductor for wet developing of the invention, by employing a hole-transfer agent having a specific structure, only a small amount of the hole-transfer agent is eluted even after long-term immersion in hydrocarbon-based solvent used as a developer for wet developing. And the electrophotographic photoconductor for wet developing may also provide excellent solvent resistance and durability because the hole-transfer agent has good compatibility with the binder resin.

Problems solved by technology

However, the conventional electrophotographic photoconductor for wet developing has a disadvantage in that it tends to be suffered from liquid developer called “Isopar” when the photoconductors are used for an extended period of time.

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